Element Cascader is a tree-like data structure for selecting items in a dropdown menu, similar to the jQuery UI's Select plugin. It allows you to create a dropdown menu with child nodes and sub-nodes, where each child node represents a separate category of items, and each sub-node represents a specific item within that category. Element Cascader uses the CSS Select plugin to create the dropdown menu, and it also provides a set of JavaScript methods for manipulating the selected items, such as filtering, sorting, and pagination. Element Cascader is often used in web applications to provide a dropdown menu with customizable options for selecting items. It can be easily integrated into a web page using JavaScript, and it can also be used to create a tree-like data structure for displaying information, such as products or categories.